This application is based upon Japanese Patent Application No. HEI 11-184,469, filed Jun. 29, 1999, which is hereby expressly incorporated by reference in its entirety.
1. Field of the Invention
The present invention generally relates to steering and lubrication systems for land vehicles. More particularly, the present invention relates to positioning various components of such system in land vehicles, such as a snowmobiles, to accommodate both systems while maintaining adequate ground clearance.
2. Description of Related Art
Snowmobiles are popular land vehicles that are used primarily in the winter and in cold and snowy conditions. Because of the terrain on which they operate, snowmobiles often contact hidden obstacles, such as rock and logs, that are buried in the snow. Snowmobiles, therefore, often are soundly designed with an eye on reducing damage to the snowmobile caused by encounters with such obstacles.
A typical snowmobile includes a frame assembly, an endless drive belt and a slide rail assembly that supports the drive on a side opposite the side that engages the terrain for propelling the snowmobile along the terrain. The frame assembly carries an engine which powers the drive belt through a suitable transmission and drive mechanism. Two steering skis depend from the frame assembly for steering the snowmobile. A steering handle extends to the rider""s area from the frame assembly so that the rider can operate it. A steering linkage couples the steering skis and the steering handle.
Snowmobile designers have recently been implementing four stroke engines in order to reduce emissions during engine operation. Typically, however, the size of the engine body of a four cycle engine is greater than the size of the engine body of a two cycle engine. One of the reasons is that the four cycle engine has a lubrication system which is much different from that of the two cycle engine. Particularly, a bottom end portion of the engine generally defines an enlarged oil pan in which lubricant oil accumulates. Thus, the overall vertical height of the engine is increased by the oil pan.
The steering linkage between the operator controls and the steering skis generally must extend beyond the engine. Typically, the linkage will pass into an area where the oil pan of a four-cycle engine is positioned. Thus, to accommodate the steering linkage, either the engine has to be raised or the linkage must be lowered. Raising the engine disadvantageously raises the center of gravity of the snowmobile; however, if the linkage is lowered to a position adequately below the engine, the steering linkage portion is much more likely to contact the terrain during operation of the snowmobile. Such contact can damage the steering system.
A need therefore exists for an improved land vehicle that can keep a steering linkage portion spaced apart from the terrain with a sufficient distance even though an engine for the vehicle has an oil pan placed generally at a bottom thereof.
One aspect of the present invention involves a snowmobile comprising a frame assembly. A drive assembly depends from the frame assembly and is adapted to abut on the terrain so as to propel the snowmobile along the terrain. An internal combustion engine is carried by the frame assembly so as to power the drive assembly. The engine includes an oil pan in which lubricant oil accumulates. The oil pan is positioned generally at a bottom end of the engine. A steering ski depends from the frame assembly for steering movement. A steering linkage extends through the frame assembly and is arranged to steer the ski. The steering linkage and the oil pan, at least in part, are generally horizontally juxtaposed with each other.
Another aspect of the present invention comprises a land vehicle comprising a body frame. A drive unit depends from the body frame and is adapted to abut on the terrain so as to propel the vehicle along the terrain. An internal combustion engine is carried by the body frame so as to power the drive unit. The engine includes an oil pan in which lubricant oil accumulates. The oil pan is positioned generally at a bottom of the engine. A steering assembly depends from the body frame for steering movement. The steering assembly includes an abutting member adapted to abut on the terrain. A steering linkage extends through the body frame and is arranged to steer the steering member. The steering linkage and the oil pan, at least in part, are generally horizontally juxtaposed with each other.
Another aspect of the present invention involves a vehicle comprising a frame assembly with at least one steerable member supporting the frame and contacting a surface over which the vehicle operates. A control mast is positioned rearward of the at least one steerable member with a linkage extending between the control mast and the at least one steerable member. The linkage comprises a rotating link and a translating link with the rotating link extending between the control mast and the translating link. An internal combustion engine is mounted to the frame assembly and is positioned between the at least one steerable member and the control mast. The engine comprises an oil pan having a lower surface and the translating link extends from the rotating link forward to a location forward of the oil pan along a portion of the oil pan at a position above the lower surface.
A further aspect of the present invention involves a vehicle comprising a frame assembly and at least one steerable member supporting the frame and contacting a surface over which the vehicle operates. A control mast is positioned rearward of the at least one steerable member with a linkage extending between the control mast and the at least one steerable member. The linkage comprises a rotating link and a translating link with the rotating link extending between the control mast and the translating link. An internal combustion engine is mounted to the frame assembly and is positioned between the at least one steerable member and the control mast. The engine comprises an oil pan having a lower surface and an auxiliary chamber. The auxiliary chamber is defined by a cover and is positioned to a side of the engine. A longitudinally extending recess is formed in a lower portion of the engine between at least a portion of the oil pan and at least a portion of the cover with the translating link extending in a longitudinal direction within the recess.
Further aspects, features and advantages of this invention will become apparent from the detailed description of the preferred embodiment which follows.